1. Field of the Invention
This invention relates to electronic circuits and more particularly to a system for stimulating electronic warfare equipment.
2. Description of the Prior Art
Man has engaged in war on the land, in the sea, in the air and in the electromagnetic spectrum. The electromagnetic spectrum has been used by the military for improved communications, the guidance of aircraft and missiles and the navigation of ships and planes. A nation seeks control of the electromagnetic spectrum because of the military's increasing dependency on its use for surveillance of potential enemy forces, communications between military units, detection of enemy military forces and the guidance and control of aeroplanes and missiles. With a mastery of the electromagnetic spectrum one adversary could achieve an indispensible ingredient for conquering an enemy or discouraging a potential aggressor.
There are two types of electronic warfare equipment, active and passive. Active equipment radiates its own energy whereas passive equipment does not. The passive category includes reconnaissance or surveillance equipment that detects and analyzes the electromagnetic radiation that is produced by radar and communications transmitters aboard aircraft, missiles, ships, satellites and ground installations. The reconnaissance devices may be used to identify and map the location of the emitters without in any way altering the nature of the signal they receive.
Certain types of passive electronic warfare systems enhance or change the nature of the electromagnetic energy reflected back to the enemy radars without generating any signal of their own. Active electronic warfare systems generate energy or delay the received signals to confuse the enemy's electromagnetic sensors.
A radar warning receiver is a passive type of electronic warfare equipment which is not used over the entire range of the electromagnetic spectrum. The radar warning receiver alerts the pilot or ship's captain that his aircraft or ship is being illuminated by a specific radar signal. Once the pilot or captain has been alerted that his vehicle has been detected by radar he can maneuver his vehicle to evade the threat or initiate certain electronic warfare countermeasures. Electronic countermeasures include all actions taken by the pilot or ship's captain to nullify the effective operation of the enemy's electronic warfare equipment. Some electronic countermeasures used are jamming the enemy's signal, the dropping of chaff and the launching of decoys.
Electronic warfare equipment is expensive, complex and difficult to learn how to operate. Simulators and other training devices have been invented to teach students to use and operate various types of equipment without undergoing the dangers that are inherent in the equipment's actual operation. For instance, it is a great deal safer and more economical to learn how to operate electronic warfare equipment on the ground in a simulator than in an actual aircraft or ship. Simulators streamline and cut the cost of training by allowing more intensive training time by permitting an instructor to control the various conditions that exist in the system being simulated. The instructor may make the student believe that enemy radar is looking at his airplane or ship or that a surface to air missile has been fired at his ship or airplane. The instructor observes and monitors the student's performance in handling the adverse conditions that are presented to him. If a student makes a mistake and does not take the proper countermeasures to avoid the surface to air missile, the student is not hurt and no damage is done to any property.
The systems used in the prior art do not simulate all the characteristics of the different types of threats that the pilot or ship's captain might see. Systems used in the prior art did not stimulate the analyzer characteristics of the aircraft's radar warning receivers and additional hardware was required when the signal strength of various radar emitters needed to be changed.